A 35-year-old man presents with central obesity, purple striae, hypertension, and proximal muscle weakness. A 1 mg overnight dexamethasone suppression...

Question

A 35-year-old man presents with central obesity, purple striae, hypertension, and proximal muscle weakness. A 1 mg overnight dexamethasone suppression test shows a morning cortisol of 12 mcg/dL (not suppressed). What is the next best test to distinguish ACTH-dependent from ACTH-independent causes?

Accepted Answer

Plasma ACTH level

Answer

24-hour urinary catecholamines

Answer

Serum aldosterone level

Answer

Plasma renin activity

Answer

Oral glucose tolerance test

us-abim MCQ (SBA): Cushing syndrome evaluation

A 35-year-old man presents with central obesity, purple striae, hypertension, and proximal muscle weakness. A 1 mg overnight dexamethasone suppression test shows a morning cortisol of 12 mcg/dL (not suppressed). What is the next best test to distinguish ACTH-dependent from ACTH-independent causes?